.duanzilist {
    width: 100%;
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
}

.duanzilist li{
    width: 30%;
    height: 200px;
    list-style: none;
    border:1px dashed black;
    margin: 10px ;
}

.duanzilist li:hover {
    cursor: pointer;
    background-color: gray;
}
.duanzilist li h5{
    text-align: center;
}
.bg{
    position: fixed;
    top:0;
    right: 0;
    bottom: 0;
    left: 0;
    background-color: rgba(0,0,0,0.5);
}

.bg .content {
    padding: 20px;
    width: 500px;
    height: 300px;
    background-color: white;
    border: 5px solid black;
    position: fixed;
    top:50%;
    left: 50%;
    transform: translate(-50%,-50%);
    overflow: auto;
}

.bg span {
    float: right;
    cursor: pointer;
}